The mandate and its narrow exemption create a “two-class scheme” of religious organizations that “honors acts of worship while burdening those whose faith leads them to service in our common life,” they argued.

In a June 11 letter to Secretary of Health and Human Services Kathleen Sebelius, the leaders voiced “grave concern” over the two-class concept of religious organizations that was “embedded in federal law” in February, when the mandate was finalized in its original form.

The letter was organized by the Institutional Religious Freedom Alliance, a D.C.-based coalition that works to protect the religious identity and work of faith-based organizations throughout America.

It was signed by aid organizations including World Relief and the U.S. branches of the Salvation Army and World Vision, Inc.

The National Association of Evangelicals, the National Hispanic Christian Leadership Conference and the North American Baptist Conference were also represented in the letter, as well as law organizations such as Liberty Counsel and the American Center for Law and Justice.

Representatives of several Catholic colleges also signed the letter, including the presidents of Aquinas College, DeSales University and Belmont Abbey College.

The letter criticized an insurance mandate issued by Sebelius that will require employers to offer health care plans that include coverage of contraception, sterilization and abortion-inducing drugs, even if doing so violates their consciences.

Although the mandate includes a religious exemption, it is extremely narrow. To qualify for it, nonprofit organizations must exist for the purpose of inculcating religious values and both serve and employ primarily members of their own faith.

Therefore, while many houses of worship fall under the protection of the exemption, most other religious organizations, including schools, hospitals and charitable agencies, do not.

The signers of the coalition’s letter note that they represent a variety of religious backgrounds, serve in different fields, and disagree about “the moral acceptability of the contraceptive drugs” and procedures included in the mandate.

They also hold differing views about the adequacy of the future “accommodation” promised by the administration for non-exempt groups.

However, they said, “we are united in opposition to the creation in federal law of two classes of religious organizations.”

Under the mandate, they explained, churches are deemed “sufficiently focused inwardly to merit an exemption and thus full protection from the mandate,” while faith-based service organizations, which have a more outward focus, are “given a lesser degree of protection.”

“And yet both worship-oriented and service-oriented religious organizations are authentically and equally religious organizations,” they said, arguing that the federal government lacks the authority to define for religious communities “what constitutes true religion and authentic ministry.”

The signatories acknowledged that the Obama administration has said that its narrow definition of “religious employer” is not intended to set a precedent in federal law.

“Yet these are only intentions,” they said, and the narrow exemption finalized with the mandate “can only make it more likely to be used in additional federal policies.”

They also warned that creating classes of religious groups “moves us further toward an unconstitutional, unhistorical, and unhealthy naked public square.”

For these reasons, the signers of the letter said, the only adequate solution is to “eliminate the two-class scheme of religious organization” that is currently present in the mandate.

They urged Sebelius to extend the exemption to all faith-based service groups in order to restore the government’s “full respect” for religious organizations as “authentic vehicles for religious service.”